Self-contained air conditioning units of the room cooler type



Dec. 22, 1959 w. L. M GRATH ETAL 2,917,905

SELF-CONTAINED AIR CONDITIONING UNITS OF THE ROOM COOLER TYPE Fi'ledJan. 5, 1954 s Sheets-Sheet 1 1 r H 4% FIG.| 1 4 H INVENTOR. 3! WM 4,lauzz,

Dec. 22, 1959 w, McGRATH ETAL 2,917,905

SELF-CONTAINED AIR CONDITIONING UNITS OF THE ROOM COOLER TYPE Filed Jan.5, 1954 s Sheets-Sheet 2 v I INVENTOR.

Z- ZQGM y a M Dec. 22, 1959 w. MCGRATH ET AL 2,917,905

SELF-CONTAINED AIR CONDITIONING UNITS OF THE ROOM COOLER TYPE Filed Jan.5, 1954 3 Sheets-Sheet 3 FIG.4

36 FIG.5

United States Patent SELF-CONTAINED AIR CONDITIONING UNITS OF THE ROOMCOOLER TYPE William L. McGrath and Francis D. Stevens, Syracuse, N.Y.,assignors to Carrier Corporation, Syracuse, N.Y., a corporation ofDelaware Application January 5, 1954, Serial No. 402,260

'5 Claims. (Cl. 62-183) This invention relates to self-contained airconditioning units, such as room coolers and, more particularly, to aunit of this type which may be placed Within a building opening such asa window frame extending for substantially its length, if desired,without the opening to present a so-called hide-away appearance of theunit within a room being treated.

Conditioners of this general type heretofore have been designed in suchmanner that the cooling portion of the unit extends within the roombeing treated while the heat removal or condensing portion of the unitextends without the room being treated. Frequently, such units do notharmonize with the decorative scheme of the room so that a unit impartsan incongruous appearance to the room. This is necessarily so since as acommercial matter, it is impossible to provide a color scheme for theunits which will harmonize with all decorative schemes; additionally,the fact that such a large portion of the unit necessarily protrudeswithin the room from a window frame detracts from or destroys thedesired appearance of the room.

The chief object of the present invention is to provide a selfcontainedair conditioning unit of the room cooler type in which substantially theentire unit may be disposed exteriorly of the room extending from thewindow opening so that the decorative scheme of the room to be treatedis not marred by the incongruous appearance of the unit.

An object of the invention is to provide a self-contained airconditioning unit of the room cooler type in which the casing of theunit is so designed that a desired portion of the complete unit mayextend without or within the room in accordance with the requirements ofthe installation.

A further object is to provide a self-contained air conditioning unit ofthe room cooler type in which room air to be cooled is passed aplurality of times through the heat exchange member of the unit thusproviding more satisfactory cooling and dehumidification of such air.

A still further object is to provide simple control mechanism for unitsof this type which prevents formation of frost on the heat exchangemember which may interfere with the capacity of the unit.

This invention relates to an air conditioning unit of the room coolertype which comprises, in combination, a substantially U-shaped basemember forming the bottom and opposite sides of the unit, a partitionextending across the unit from one side of the base member to theopposite side of the base member to divide the unit into a firstcompartment and a second compartment, a refrigeration system placed onsaid base member including an evaporator and a condenser, the evaporatorbeing placed in the first compartment and the condenser being placed inthe second compartment and forming, in effect, the rear wall of theunit, a cover fitting over the sides of the base member, means forpassing air through the evaporator to cool the same and means forpassing air through the 2,917,905 Patented Dec. 22, 1959 condenser tocondense refrigerant of the refrigeration system.

This invention further relates to an air conditioning unit of the roomcooler type which comprises, in combination, an enclosure, a partitionextending across the enclosure from one side to the opposite side toform the enclosure into a first compartment and a second compartment, arefrigeration system in said unit including an evaporator and acondenser, the evaporator being placed in the first compartment and thecondenser being placed in the second compartment and forming, in effect,the rear wall of the enclosure, means for drawing air through oneportion of the evaporator to cool the same and for passing the cooledair through a second portion of the evaporator to further cool the sameand means for drawing air through one portion of the condenser and forpassing the same air through a second portion of the condenser to removethe heat absorbed by the refrigeration system.

This invention further relates to a method of operation of a roomcooling unit in which the steps consist in passing a first air streamthrough one side of a coil forming the evaporator of a refrigerationsystem to reduce its dry bulb temperature, reversing the direction offlow of the cooled air stream and passing the same through the otherside of the coil to further reduce its temperature, discharging thecooled air into the room to be treated and carrying away the heatremoved from the first air stream by passing a second air stream in heatexchange relation with refrigerant in the condenser of the refrigerationsystem.

The attached drawings illustrate preferred embodiments of our invention,in which Figure 1 is an isometric view of the self-contained airconditioning unit of the present invention disposed in a desiredposition within a building opening such as a window frame;

Figure 2 is a plan view of the unit shown in Figure 1 with its cover andgrille removed;

Figure 3 is an isometric view of the base member of the unit,illustrating a modification in the manner in which the evaporator fan isplaced in the unit;

Figure 4 is a sectional view of the unit illustrating simple controlmechanism to prevent frosting of the evaporator coil; and

Figure 5 is a view in elevation illustrating the condenser fin coilconstruction.

Referring to the drawings, there is disclosed the air conditioning unit2 of the room cooler type disposed in place in a building opening asformed, for example, by the window frame 3. It will be appreciated thatany desired portion of the unit may extend exteriorly of the opening topresent a so-called hide-away appearance within the room being treated.A picture-frame gasket of the ring type (not shown) is placed around theunit. Wing panels 4- are placed between the unit and opposite sides ofthe frame 3 to close the space therebetween. The Window 5 is then moveddownward to compress the gasket so as to complete the seal about theunit when it is disposed in desired position.

The manner of installation of the unit is shown and claimed in ourcopending application, Serial No. 402,364, filed January 5, 1954, towhich reference is made for a more complete description of the manner ofinstallation of the unit.

Unit 2 includes a box-like casing 6 formed of a U-shaped base member 7forming the bottom 8 and sides 9, 10 of the unit, a cover 11 which fitsover the sides 9, 10, and a grille member 12 which fits over the frontof the unit. Grille member 12 is provided with inlets 13 and outlets 14as hereinafter described. This construction provides a casing which maybe placed in any suitable position within the building opening and doesnot 3 require that any specific length of the unit extend within theroom being treated. Thus, a ring-like gasket may be applied about theunit in different positions to seal the unit when it is disposed inplace in a building structure.

A partition 15 extends substantially from side to side of the unit andfrom the cover to the bottom to separate the unit into a firstcompartment 16 and a second compartment 17. An opening 18 is formedwithin partition 15 and is closed by a damper or bafile member 19 for apurpose hereinafter explained. Baffle 19 may be moved by suitablemechanism 20 to a first position, shown in dotted outline in Figure 2,to permit air to flow from compartment 17 through opening 18 intocompartment 16, and may be returned to its initial position by releasingsuch mechanism to permit spring 21 connected between bafile 19 and anarm 22 attached to partition 15 or to the casing to return the baffle toinitial position. If desired, suitable sealing material (not shown) maybe placed about the opening or on the bafile to assure that asubstantial volume of air does not leak into compartment 16 when theopening is closed.

To cool air drawn into the unit, a refrigeration system designatedgenerally at 25 is provided. The refrigeration system 25 includes acompressor 26 driven by a motor 27 connected to a suitable source ofelectrical energy; preferably, compressor 26 and motor 27 are combinedin a hermetic or semi-hermetic unit. Compressor 26 is connected to acondenser 28 which extends, preferably from side to side of U-shapedbase member 7 and in effect forms the rear wall of casing 6. Preferably,condenser 28 is a plate fin coil, well known in the industry. Condenser28 is connected to evaporator 29, a capillary tube (not shown)regulating flow of refrigerant from the condenser to the evaporator.Evaporator 29 is placed in compartment 16 and extends, preferably, fromside to side of member 7. The evaporator 29 is connected to compressor26 to return evaporated refrigerant to the compressor, an accumulator 30being placed in the circuit between evaporator 29 and compressor 26 toprevent unevaporated refrigerant from returning to the compressor.

As shown in Figure 2, a fan compartment 31 is formed within compartment16 adjacent the evaporator coil 29. Fan 32 is placed within thecompartment and serves to draw room air through inlets 13 of grille 12and one portion 33 of the evaporator 29 to cool the same and to pass thecooled air through a second portion 34 of evaporator 29 to further coolthe same, discharging the cooled air through outlets 14 of grille 12into the room being treated.

A fan compartment 35 is placed in compartment 17 adjacent the condensercoil 28, fan 36 being placed in such compartment. Fan 36 draws air fromthe exterior of the building through a first portion 37 of condenser 28over the compressor and motor to cool the compressor and motor and thendischarges the air through a second portion 38 of the condenser 28exteriorly of the building. Passage of air through the condensercondenses the gaseous refrigerant and removes the heat from the systemabsorbed by refrigerant in the evaporator from the room air. If desired,a bafile (not shown) may be placed to extend rearwardly from thecondenser to assure that the heated air after passage through thecondenser is not drawn immediately into the first condenser portion 37.Preferably, however, the exterior edge portions 80 of the plate fins 81of condenser coil 28 are bent at an angle, as shown in Figure 5, toprevent heated air being drawn into the condenser. Fins in condenserportion 37 are bent toward the outer edge of the coil while the fins incondenser portion 38 are bent in the opposite direction.

Fans 32 and 36 may be actuated by motor 39 connected to the source ofelectrical supply. If desired, however, these fans may, of course, beactuated by separate motors.

It should be noted that when baffle 19 is opened to its full extent, itabuts evaporator fan compartment 31 permitting fan 32 to draw air fromcompartment 17 for ventilation within the room being treated andpreventing the plural passes of air through the evaporator coil.

When the unit 2 is installed in position in a building, preferably, itis tilted or pitched to permit condensate collected by the evaporator topass into the condenser compartment and collect in a sump (not. shown).A slinger (not shown) is provided to fling the condensate into the airpassing over the condenser and on the condenser coil thus evaporatingthe condensate to remove collected moisture from the unit. Openings 40may be provided in partition 15 to permit the condensate to flow fromcompartment 16 to compartment 17. Porous, sponge-like absorbent members41 are placed in openings 40 to prevent too rapid flow of condensateaccumulated under certain conditions. Thus, the amount of condensateaccumulated in compartment 17 is never so great as to overflow the unit,all condensate collected being dissipated or evaporated in the heatedair stream discharged from the unit.

Considering the operation of the unit 2, fan 32 draws room air throughinlets 13 in grille 12, through the first portion 33 of the evaporator29 in heat exchange relation with refrigerant therein to cool the airand then pass the cooled air stream through the second portion 34 of theevaporator in heat exchange relation with refrigerant therein to furthercool the air, the cooled air being discharged into the room throughoutlets 14 in grille 12. The evaporated refrigerant is condensed incondenser 28, fan 36 drawing outside air through portion 37 of thecondenser and then passing the condensed air through the second portion38 of the condenser.

When it is desired to provide ventilation air for the room beingtreated, damper or bafile 19 is opened to a desired extent thuspermitting fan 32 to mix a stream of air from compartment 17 with airbeing drawn through portion 33 of evaporator 29. It will be appreciatedthe volume of the air stream drawn from the room through evaporatorportion 33 is reduced when the damper 19 is opened since the open damperin effect blocks 05 a portion of such air stream in accordance with themanner in which it is opened so that the volume of cooled air dischargedinto the room remains substantially constant. If the damper is opened toits full extent, it abuts against fan compartment 31 thus effectivelypreventing passage of room air through evaporator portion 33. This isparticularly desirable when ventilation air only is being supplied byoperation of fan 32, it not being desired to cool such air so that therefrigeration system is not in operation.

In Figure 3, I have shown a somewhat different arrangement of theevaporator fan. In this case fan compartment 45 is placed centrally ofthe evaporator coil 29, fan 47 being placed therein to draw room airthrough the two opposite sides 48, 49 of coil 29 and passing such airthrough the central portion 50 of the coil to discharge the same intothe room being treated. In this case, the damper 19 abuts one side ofcompartment 45 when fully open, permitting fan 47 to continue to draw adesired stream of room air into the unit for admixture with the streamof ventilation air before discharge of the mixed streams into the room.

In Figure 4, I have illustrated the unit provided with simple controlmechanism to prevent frosting of the evaporator coil. A control 55reactant to existence of frost in the evaporator coil is provided. Suchcontrol may be a thermostat responsive to the temperature of evaporatorcoil 29 which is connected to the motor 56 of condenser fan 57.Preferably, the thermostat is placed on the evaporator coil within theair stream being directed through the evaporator 29, although ifdesired, it may be placed in any other suitable location, such as thesuction line, liquid supply line, etc. Thermostat 55 is so designed thatit discontinues operation of the condenser fan 57 at a desiredevaporator coil temperature, say 26 F., and permits resumption of fanoperation at a desired higher coil temperature, say 40 F., thuspreventing frosting of the coil by cycling the condenser fan. Since thethermostat 55 is placed within the air stream being directed through theevaporator, the air passing thereover when the condenser is inoperativewarms the thermostat thus accelerating resumption of operation of thecondenser fan. This control mechanism avoids undesirable short cyclingof the compressor for the compressor continues in operation even thoughthe condenser fan is shut off. An inexpensive thermostat may beemployed.

If desired, the inlets in the grille 12 may be formed in the bottom ofthe grille and outlets may be formed in the top of the grille. Suchconstruction, of course, may require rearrangement of the position ofthe fan.

The present invention provides an air conditioning unit of the roomcooler type so designed as to permit a desired portion of its length tobe placed without a building structure. The unit is simple andinexpensive in construction and permits rapid and ready installation indesired position. After installation, the unit may be easily removed topermit window cleaning or for storage purposes, if it is not desired touse the unit in winter operation for ventilating purposes.

The unit provides more satisfactory cooling and dehumidification of roomair since the air stream passes through the evaporator coil a pluralityof times thus reducing the bypass factor. Simple control mechanism maybe provided to control room temperature and to prevent frosting of theevaporator coil or ready removal of collected frost from the evaporatorcoil. Means are provided to prevent condensate overflowing the unit whenconditions of excessive humidity are encountered. An advantage of thecondenser design resides in the fact that leaves are not drawn into theunit while the closed casing structure prevents birds nesting within theunit.

While we have described a preferred embodiment of our invention, it willbe understood that our invention is not limited thereto since it may beotherwise embodied within the scope of the following claims.

We claim:

1. In an air conditioning unit, the combination of a substantiallyU-shaped base member forming the bottom and opposite sides of the unit,a partition extending across the unit from one side of the base memberto the opposite side of the base member to divide the unit into a firstcompartment and a second compartment, a refrigeration system placed onsaid base member including an evaporator and a condenser, the evaporatorbeing placed in the first compartment and the condenser being placed inthe second compartment and forming, in effect, the rear wall of theunit, a cover fitting over the sides of the base member, means forpassing air through the evaporator to cool the same, means for passingair through the condenser to condense refrigerant of the refrigerationsystem, said partition having an opening therein adjacent to the basemember, and a porous, absorbent, sponge-like member placed in saidopening to regulate flow of condensate from the evaporator compartmentto the condenser compartment.

2. In an air conditioning unit, the combination of an enclosure, apartition forming the enclosure into a first compartment and a secondcompartment, a refrigeration system placed in said enclosure includingan evaporator, a compressor and a condenser, a prime mover for thecompressor, the evaporator being placed in the first compartment and thecondenser in the second compartment, means to direct a first air streamthrough the evaporator, a fan to direct a second air stream through thecondenser, a motor to operate said fan and a control responsive toevaporator temperature to actuate said condenser fan, said control inresponse to a predetermined evaporator temperature discontinuingoperation of said fan while operation of the prime mover continues toprevent substantial frosting of the evaporator and in response to a.second predetermined evaporator temperature again actuating the fan todirect the second air stream through the condenser.

3. An air conditioning unit according to claim 2 in which the control isplaced in the path of the first air stream thereby expediting actuationof the fan.

4. In an air conditioning unit, the combination of a substantiallyU-shaped base member forming the bottom and opposite sides of the unit,a partition extending across the unit from one side of the base memberto the opposite side of the base member to divide the unit into a firstcompartment and a second compartment, a refrigeration system placed onsaid base member including an evaporator, a compressor, and a condenser,and means for actuating the compressor, the evaporator being placed inthe first compartment and the condenser being placed in the secondcompartment and forming, in effect, the rear Wall of the unit, a coverfitting over the sides of the base member, means to direct a first airstream through the evaporator, a fan to direct a second air streamthrough the condenser, a motor to operate said fan, and a controlresponsive to evaporator temperature to actuate said motor, said controlin response to a predetermined evaporator temperature discontinuingoperation of said fan while actuation of the compressor is continued toprevent substantial frosting of the evaporator and in response to asecond predetermined evaporator temperature again actuating the fan todirect the second air stream through the condenser.

5. In an air conditioning unit, the combination of a substantiallyU-shaped base member forming the bottom and opposite sides of the unit,a partition extending across the unit from one side of the base to theopposite side to divide the unit into a first compartment and a secondcompartment, a cover fitting over the sides of the base member, arefrigeration system placed on the base member including an evaporator,a compressor, and a condenser, means for actuating the compressor, theevaporator being placed in the first compartment and extendingsubstantially from side to side of the base member, the condenser beingplaced in the second compartment and forming, in effect, the rear wallof the unit, means for drawing a first air stream through one portion ofthe evaporator to cool the same and for reversing the direction of flowof the first air stream to pass the cooled air through a second portionof the evaporator to further cool the same, a fan to direct a second airstream through the condenser, a motor to operate said fan, and a controlresponsive to evaporator temperature to actuate said motor, saidcontrol, in response to a predetermined evaporator temperature,discontinuing operation of the fan while actuation of the compressor iscontinued to prevent substantial frosting of the evaporator and inresponse to a second predetermined evaporator temperature againactuating the fan to direct the second air stream through the condenser.

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